This invention relates to tension control systems and more particularly to a system and method for applying a double-faced, pressure sensitive adhesive foam core tape to a trim strip.
Currently, automotive body side moldings and trim strips are manufactured from plastic material and secured to the side of automobile bodies by double-faced, pressure sensitive adhesive foam core tape. The plastic moldings are subject to some amount of stretching and stressing during processing. For example, some shrinkage of the plastic molding occurs as it cools down, and additional shrinkage occurs with aging of the molding as stresses induced therein tend to relieve themselves. Thus, when foam core tape is first applied to the hot body side molding it must be tensioned to provide a coordinated stretch with the stretch in the side molding so as to shrink and/or stretch therewith. If too great a length of foam tape is applied to a body side molding it tends to wrinkle and/or buckle thus compromising the adherence of the side molding to an automobile body.
Heretofore, double-faced pressure sensitive adhesive foam core tape was applied to a substrate such as a body side molding by employing a predetermined weight riding against the tape to create a drag thereon so as to stretch the tape at a given rate as it is being applied to the substrate. Another method of applying a pressure sensitive adhesive foam core tape to a substrate was to arch the substrate to place it in a compressed state, apply the tape to the arched substrate, and release the substrate from its arched condition to tension and stretch the foam core tape.
However, the above methods were not entirely satisfactory in that the shrinkage of the body side molding is not totally predictable making it difficult to determine the force needed to obtain the desired stretch of the tape in the first described method or the amount of arching of the body side molding in the later described method. Also, these prior methods needed tool changes for each degree of stretch required. In some cases, the necessary tooling changes required a complete shutting down of the associated production lines.